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13.18: Some Prefixes That Make < cc >

Difficulty Level: At Grade Created by: CK-12

1. What always comes before <kle>, a vowel or a consonant? a consonant What always comes before <ckle>, a long vowel, a short vowel, or a consonant? a short vowel What usually comes in front of the <cle>, a vowel or a consonant? a vowel

2. When they are added to stems that start with <c>, the three prefixes ad-, sub, and ob- assimilate to ac-, suc-, and oc-, making a <cc> toward the front of the word. Sometimes the <cc> spells the sound [k]; sometimes it spells [ks].

All of the following words contain one of these prefixes. Analyze each word into prefix and stem to show where the two <c>’s come from:

Word Prefix + Stem
accelerate ad + c + celerate
according ad + c + cord
account ad + c + count
occasionally ob + c + casionally
successful sub + c + cessful
occurrence ob + c + currence
occupy ob + c + cupy
accident ad + c + cident
accurate ad + c + curate
access ad + c + cess
occupation ob + c + cupation
accompany ad + c + company
accommodate ad + c + commodate
succinctly sub + c + cinctly
accuse ad + c + cuse
accumulate ad + c + cumulate

3. Sort the words into these two groups:

Words in which the <cc> spells ...
[k] [ks]
according occupation accelerate
account accompany successful
occasionally accommodate accident
occurrence accuse access
occupy accumulate succinctly

4. Look carefully at the letter that comes right after the <cc> in each of the words. Then sort the words into this matrix:

Words in which the <cc> spells ...
[k] [ks]
Words that have <e> or <i> following the <cc>






Words that do not have <e> or <i> following the <cc>












5. Be ready to discuss this question: Why do the words sort out the way they do in the matrix in Item 4?

Teaching Notes.

Item 2. The assimilation pattern for ad- is introduced in Book 4, Lessons 11-13. That for sub- is introduced in Book 4, Lesson 34, and that for ob- in Book 4, Lesson 37. These patterns are treated in AES as follows: ad-, pp. 188-93; sub-, pp. 183-86; ob-, pp. 195- 96.

Item 5. The discussion should get to the way in which <c> before <e>, <i>, or <y> spells soft <c>, [s], while before other letters it spells hard <c>, [k]. Thus the first <c> in <cc> must be hard since it is followed by a <c>, while the second <c> will be soft or hard, depending on the letter following it.

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Date Created:

Feb 23, 2012

Last Modified:

Jul 07, 2015
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